Place 5 large sweet potatoes on a cookie sheet in a 375F oven for about 1 hour 25 mins. Slice the sweet potatoes in half and scoop out the insides. Throw the skins away.
Lower the oven temp to 325 degrees F (165 degrees C).
In a large bowl, mix together the sweet potatoes, blue agave, eggs, salt, butter, milk, vanilla & spices. Mix until smooth. Transfer to a 9x13 inch baking dish.
In medium bowl, mix the brown sugar and flour. Cut in the butter until the mixture is coarse. Stir in the pecans. Sprinkle the mixture over the sweet potato mixture.
Bake in the preheated oven 30 minutes, or until the topping is lightly brown.